2-(alpha,alpha-bis(trifluoromethyl)benzyloxy) acetic acid and esters thereof

ABSTRACT

New compounds are disclosed which correspond to the formula WHEREIN R is hydrogen or lower alkyl. They are prepared by reacting (a) esters of chloroacetic acid or bromoacetic acid with (b) Alpha , Alpha -bis(trifluoromethyl)benzyl alcohol in the presence of strong base. They are herbicides.

United States Patent Kuhn 1 June 26, 19732-(ALPHA,ALPHA-BIS(TRIFLUOROME- Boije, C. A. 5 2 5725d (1958)THYL)BENZYLOXY) ACETIC ACID AND ESTERS THEREOF Primary Examiner-LorraineA. Weinberger Assistant Examiner-John F. Terapane [75] lnvemor' 2:52;:Kuhn Samla Ontario Att0rney-William M. Yates, L. Wayne White et al.

[73] Assrgnee: 32312:; fihzzlcal Company, ABSTRACT I New compounds aredisclosed which correspond to the [22] Filed. Apr. 24, 1972 formula [21]Appl. No.: 246,783

CF 0 [52] US. Cl 260/521 A, 260/473 A, 71/109, C HSd(CFQ)-OCHZ( ZOR,71/116 C07c wherein R is hydrogen or lower alkyl. They are pre- 266/473pared by reacting (a) esters of chloroacetic acid or bromoacetic acidwith (b) a,a-bis(trifluoromethyl)- [56] References Cited benzyl alcoholin the presence of strong base. They are OTHER PUBLICATIONS Julia et al.C. A. 76109m (1971) Vol. 75

herbicides.

2 Claims, No Drawings 2-(ALPHA,ALPHA-BIS(TRIFLUOROMETHYL)- BENZYLOXY)ACETIC ACID AND ESTERS THEREOF BACKGROUND OF THE INVENTIONa,a-Bis(trifluoromethyl)benzyl alcohol is a known compound. Cf. B. S.Farah et al., J. Org. Chem. 30, 998 (1965) and I. L. Knunyants et al.(CA. 57: 12305:). It is here used as a reactant.

SUMMARY OF THE INVENTION I have discovered a novel class of compoundswhich correspond to the formula wherein R is hydrogen or lower alkyl offrom one to four carbon atoms. The compounds are biologically active andare useful as herbicides.

The novel esters are conveniently prepared by reacting (a) esters ofchloroacetic acid or bromoacetic acid (ClCI-I2( :OR or BlCH2 'OR) with(b) a,a-bis(trifluoromethyl)benzyl alcohol. The process is generallyconducted in the presence of a strong base and in a liquid reactionmedium (e.g., benzene, toluene and the like).

When R is hydrogen in Formula I, the compound is an acid. This acid isprepared by a conventional hydrolysis of any of the above esters.

Examples of suitable such esters of chloroacetic acid and bromoaceticacid include the methyl, ethyl, npropyl, isopropyl and butyl estersthereof. Other esters can likewise be used.

EXAMPLES The following examples further illustrate the invention.Example 1 Preparation of Ethyl a,a-Bis(trifluoromethyl)benzyloxy-acetateacetate a,a-Bis(trifluoromethyl)benzyl alcohol (0.2 mole) I dissolved in100 ml. of toluene and 17.5 g. of 50 percent aqueous caustic werecharged to a reaction vessel equipped with a stirring means, heatingmeans, and a condenser. White crystals formed immediately. The reactionmixture was warmed to reflux conditions and the water removed as anazeotrope with toluene. After the water was removed, 100 ml. of tolueneand ethyl bromoacetate (0.2 mole) were charged to the vessel and thereaction mixture warmed at reflux temperature for 2 hours. The mixturewas cooled, neutralized with aqueous HCl, washed twice with 100 ml.portions of water, dried over calcium sulfate and the organic phaserecovered. The desired product was distilled from the organic phaseunder reduced pressure. The product was obtained in 86 percent yield,based on theory. Boiling point l08-l 10C. at 0.5 mm. of Hg. pressure.Refractive index n,, at 225C. 1.4273.

Calc. for C H F O C 47.3; H 3.66

Found: C 47.0; H 3.81

The product structure was also confirmed by infrared and nuclearmagnetic resonance spectra. Example 2 The ester (0.1 mole) from Example1 was heated at 60C. in ml. of 10 percent aqueous NaOH for 3-4 hours.The homogeneous solution thus formed was cooled, neutralized withconcentrated HCl, and the product extracted therefrom with methylenechloride. The crude product was then recovered by removing the methylenechloride under reduced pressure. Subsequent recrystallization of thecrude product from a hexane solution rendered the desired product as awhite crystalline solid melting at l05-l07C. Yield 95.2 percent oftheory. The product structure was confirmed by infrared, nuclearmagnetic resonance and elemental analysis.

Calc. for C I-I F O C 43.66; H 2.66

Found: C 43.56; H 2.7

The compounds of the present invention are suitable for use asherbicides in the control of yellow foxtail. For such uses, theunmodified substance can be utilized or they can be used in aformulation. Thus, for example, the subject compounds can be dispersedon a finely divided solid and employed therein as a dust. Also, thecompounds, or a solid composition comprising the compound, can bedispersed in water (typically with the aid of a wetting agent) and theresulting aqueous suspension employed as a spray. In other procedures,the subject compound can be employed as a constituent of organic liquidcompositions, oil-in-water and water-in-oil emulsions, or waterdispersions, with or without the addition of wetting, dispersing oremulsifying agents.

In representative operations, each of the ethyl (X,(1-IJI-s(trifluoromethyl)benzyloxyacetate anda,a-bis(trifluoromethyl)benzyloxy-acetic acid compounds gives completecontrol and kill of yellow foxtail when plants of such species aresprayed to run-off with compositions containing one of the above-namedcompounds at a concentration of 4000 parts per million by weight.

The following compounds are prepared and used in a similar manner:

drogen.

2. The compound defined in claim 1 wherein R is hydrogen.